Field of the Invention
This invention relates to a device for facilitating a chemical reaction, and more particularly, to a device and method for facilitating the generation of chlorine dioxide gas for release into air or water.
Background of the Prior Art
Chlorine dioxide gas is a well known disinfectant and deodorizing agent that can be generated as a gas for release into air or water. Chlorine dioxide gas is soluble and does not hydrolyze in water, but remains as a true gas in water. It is common to use sodium chlorite and an acid, both in dry form, combined with an aqueous solution to generate chlorine dioxide. The problem with conventional non-electrically powered chlorine dioxide gas generators using dry sodium chlorite and an acid has been the membrane shells forming the cavities that receive the dry sodium chlorite and acid. More specifically, prior art membranes are substantially impervious to liquid and have been designed to protect the dry internal components from moisture to promote shipping and handling of the device without activation.
Unfortunately, the water protective membranes have increased the reaction time required for completing the chlorine dioxide gas generation from the combining of the sodium chlorite and acid after exposure to water. The water protective membranes increase the reaction time because a wick member must be used to transport water into the membrane shell, thereby increasing the time required to dispose water inside the shell due to the relatively small cross sectional area of the wick penetrating the shell. Further, although the membranes are semi-permeable to chlorine dioxide gas, the flow of chlorine dioxide gas is restricted through the membranes during gas generation thereby restricting “breathability” of the shell.
Another problem with prior art chlorine dioxide gas generators is that only one cavity is provided to receive a mixture of sodium chlorite and acid. The mixing of the reactants results in inconsistencies and varying contact ratios between the sodium chlorite and acid resulting in varying quantities of chlorine dioxide gas being generated when water engages the reactants.
The mixed internal components form different surface areas of sodium chlorite that engage acid relative to the wick member. When water initially engages the internal components adjacent to the wick member, then travels to internal components further from the wick member, varying amounts sodium chlorite react with varying amounts of acid, thereby providing slower and/or incomplete reactions between the sodium chlorite and acid, resulting in wasted residual portions of each internal component which must be discarded and which did not generate any chlorine dioxide.
U.S. Pat. No. 5,126,070, issued to Leifheit et al. on Jun. 30, 1992, discloses a rupturable or frangible pouch and an absorbent carrier for reacting a chlorite and an acid to form chlorine dioxide gas. The speed of chlorine dioxide gas formation is dependent upon the manual force applied to the package to combine the internal components.
U.S. Pat. No. 6,764,661, issued to Girard on Jul. 20, 2004, discloses wick means extending into and connected to a membrane shell defining a compartment. A wick member extends outside of the compartment. The wick member absorbs water outside of the compartment and transports the water into the compartment to expose the components therein to water to produce chlorine dioxide gas.
In general, the prior art devices and methods do not provide sufficient surface area to fully utilize all of the supplied chemical and to cause a complete reaction between sodium chlorite and acid such that there is no “unused” portions of either component, which results in a less than maximum formation of chlorine dioxide gas. More specifically, the prior art devices resort to manual force or added components (wick means) to urge the engagement of sodium chlorite, acid and water instead of using the relatively large surface area of the packet containing the components to ultimately expose the components to an aqueous solution. Further, the prior art devices do not use a material for constructing the packets or shells that are capable of allowing a relatively large quantity of water to flow relatively quickly through the shell to engage the internal components, and that allows generated chlorine dioxide gas to escape relatively fast through shell and into the surrounding air and/or water. Also, although the material of construction should allow water through the shell, the material must resist atmospheric moisture to prevent premature activation of the internal components. Another problem with the prior art is that the packets are not rigid and therefore change shape after disposing dry reactants into chambers, resulting in less than full chambers, non-uniform distribution of the dry chemicals in the packet, and dry chemicals that vary in configuration when the orientation of the packet is changed, thereby reducing chlorine dioxide generation and allowing residual unused chemicals.